1. Field of the Invention
The present invention relates to a polymer compound, a chemically amplified negative resist composition using the polymer compound, a photo-curable dry film formed by using the chemically amplified negative resist composition and a production method thereof, a layered product having the photo-curable dry film laminated on a substrate, a patterning process using the chemically amplified negative resist composition and the photo-curable dry film, and a substrate obtained by the patterning process.
2. Description of the Related Art
In accordance with progress of various electronic devices including a personal computer, a digital camera, and a mobile phone toward downsizing and higher performance, requirements are also rapidly increasing for further downsizing, thinning, and higher density in a semiconductor device. Accordingly, development of a photosensitive insulation material is wanted which can respond not only to an increase in surface area of a substrate for the sake of higher productivity but also to a structural body having fine concavity and convexity with a high aspect ratio on a substrate in high density mounting technologies including a chip size packaging or a chip scale packaging (CSP), and a three dimensional lamination.
As to the photosensitive insulating material as mentioned above, a proposal is made (Patent Document 1) with regard to a photo-curable resin composition that can provide a top coat film to protect electric and electronic parts; the composition being capable of coating so as to give a wide range of film thickness by a spin coating method that is usually used in manufacturing process of a semiconductor device, capable of fine patterning in a wide range of wavelength, and having excellent flexibility, heat resistance, electric characteristics, adhesiveness, reliability, and chemical resistance by post-cure at low temperature. This spin coating method has an advantage that a film can be conveniently formed on a substrate.
On the other hand, although the above-mentioned photo-curable resin composition to provide the top coat film to protect electric and electronic parts is used with the film thickness of 1 to 100 μm on a substrate, practically there is a limit in the photo-curable resin composition because when the film thickness thereof goes beyond about 30 μm, its viscosity coefficient becomes so high that to form a film on a substrate by a spin coating method becomes difficult.
In addition, it is difficult to cover the substrate almost evenly by the photo-curable resin composition when it is applied by a spin coating method on a substrate having a concavity and a convexity on its surface. Because of this, the photo-curable resin layer tends to readily form a space on the uneven part of the substrate; and thus, further improvements in flattening and in covering of the uneven surface have been waited. As the alternative coating method in place of a spin coating method, a spray coating method is proposed (Patent Document 2). However, in principle, this method tends to readily cause defects such as different heights due to the concavity and the convexity of a substrate, film loss in the pattern edge, and a pinhole in the concavity bottom; and thus, problems related to flattening and covering of the uneven surface have not been fully solved yet.
In recent years, in high density mounting technologies including a chip size packaging or a chip scale packaging (CSP) and a three dimensional lamination, a technology by which a fine pattern having a high aspect ratio is formed on a substrate, followed by laminating the pattern thus obtained with a metal including copper whereby rewiring from a chip is very active. As the chip advances toward higher density and integration, requirements for miniaturization of a pattern width and a contact hole size to connect between substrates in the rewiring technology is very strong. To obtain a fine pattern, a lithography technology is generally used, and among others, a chemically amplified negative resist composition is suitable to obtain a fine pattern. Moreover, the pattern used for rewiring not only permanently exists in a device and between chips but also needs to work as a top coat film that is curable and also has excellent flexibility, heat resistance, electric characteristics, adhesiveness, reliability, and chemical resistance to protect electric and electronic parts; and therefore, it is said that the resist composition to obtain the pattern is preferably of a negative type.
As mentioned above, a chemically amplified negative resist composition is suitable as the composition for a patterning process that is capable of processing a fine rewire and of forming a top coat film having excellent flexibility, heat resistance, electric characteristics, adhesiveness, reliability, and chemical resistance to protect electric and electronic parts.